Final answer:
Charles Lyell advocated for uniformitarianism in geology, proposing that geological change occurs slowly and consistently over time. He provided evidence such as the formation of valleys and sedimentary layers to support his ideas.
Step-by-step explanation:
Charles Lyell was a Scottish geologist who advocated for the principle of uniformitarianism in geology. This principle suggests that the same geological processes operating in the present have also operated in the past, at the same rate. Lyell argued that geological phenomena were the result of slow forces acting over vast periods of time.
Lyell provided several lines of evidence to support his ideas. One example is the formation of valleys by rivers wearing through rock. He observed that this process occurs gradually over time, indicating that geological change happens slowly. Another line of evidence was the formation of sedimentary layers, which he believed were formed by the accumulation of deposits over long periods of time.
In summary, Lyell's geological ideas about change were based on the principle of uniformitarianism, which states that geological processes occur slowly and consistently over vast periods of time. He supported his ideas with evidence such as the gradual formation of valleys and sedimentary layers.